We first characterized immune subsets in lymphoid and target organs within the cGVHD pre-clinical model. We then completed in vivo cell kinetics experiments in the said model, and identified differential patterns for cGVHD versus control cohorts. We, then, developed a non-radioactive imaging modality for cGVHD. So far, we have been able to image cGVHD-affected organs in the pre-clinical setting, and our current efforts are directed towards testing this imaging approach for patients undergoing hematopoietic stem cell transplantation with and without resultant immune dysregulation.